Subjects included RNs, LPNs, and Nas with a minimum of 6 months experience and a job description that included a minimum of 80% direct patient care responsibilities. Subjects were required to be injury free for at least one year, as evidenced by a brief orthopedic examination and interview. The orthopedic evaluation included an examination of posture, gait, range of motion, sensory deficits, muscle exam, and straight leg raise. We excluded subjects with self-report of injury or any positive finding of back musculoskeletal disorders within the past 12 months.